Skip _extends helper for {…x} with modern targets (#12899)

packages/babel-plugin-proposal-object-rest-spread/package.json

@@ -17,6 +17,8 @@
     "babel-plugin"
   ],
   "dependencies": {
+    "@babel/compat-data": "workspace:^7.13.6",
+    "@babel/helper-compilation-targets": "workspace:^7.13.0",
     "@babel/helper-plugin-utils": "workspace:^7.13.0",
     "@babel/plugin-syntax-object-rest-spread": "^7.8.3",
     "@babel/plugin-transform-parameters": "workspace:^7.13.0"

packages/babel-plugin-proposal-object-rest-spread/src/index.js

@@ -2,6 +2,8 @@ import { declare } from "@babel/helper-plugin-utils";
 import syntaxObjectRestSpread from "@babel/plugin-syntax-object-rest-spread";
 import { types as t } from "@babel/core";
 import { convertFunctionParams } from "@babel/plugin-transform-parameters";
+import { isRequired } from "@babel/helper-compilation-targets";
+import compatData from "@babel/compat-data/corejs2-built-ins";
 
 // TODO: Remove in Babel 8
 // @babel/types <=7.3.3 counts FOO as referenced in var { x: FOO }.
@@ -17,7 +19,12 @@ const ZERO_REFS = (() => {
 export default declare((api, opts) => {
   api.assertVersion(7);
 
-  const { useBuiltIns = false, loose = false } = opts;
+  const targets = api.targets();
+  const supportsObjectAssign = !isRequired("es6.object.assign", targets, {
+    compatData,
+  });
+
+  const { useBuiltIns = supportsObjectAssign, loose = false } = opts;
 
   if (typeof loose !== "boolean") {
     throw new Error(".loose must be a boolean, or undefined");

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/assumption-setSpreadProperties/targets-support-object-assign/input.js

@@ -0,0 +1 @@
+let a = { x: 1, ...b };

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/assumption-setSpreadProperties/targets-support-object-assign/options.json

@@ -0,0 +1,3 @@
+{
+  "targets": "firefox 70"
+}

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/assumption-setSpreadProperties/targets-support-object-assign/output.js

@@ -0,0 +1,3 @@
+let a = Object.assign({
+  x: 1
+}, b);

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread-loose/targets-support-object-assign/input.js

@@ -0,0 +1 @@
+let a = { x: 1, ...b };

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread-loose/targets-support-object-assign/options.json

@@ -0,0 +1,3 @@
+{
+  "targets": "firefox 70"
+}

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread-loose/targets-support-object-assign/output.js

@@ -0,0 +1,3 @@
+let a = Object.assign({
+  x: 1
+}, b);

yarn.lock

@@ -139,7 +139,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@babel/compat-data@workspace:^7.13.0, @babel/compat-data@workspace:^7.13.5, @babel/compat-data@workspace:packages/babel-compat-data":
+"@babel/compat-data@workspace:^7.13.0, @babel/compat-data@workspace:^7.13.5, @babel/compat-data@workspace:^7.13.6, @babel/compat-data@workspace:packages/babel-compat-data":
   version: 0.0.0-use.local
   resolution: "@babel/compat-data@workspace:packages/babel-compat-data"
   dependencies:
@@ -1287,7 +1287,9 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@babel/plugin-proposal-object-rest-spread@workspace:packages/babel-plugin-proposal-object-rest-spread"
   dependencies:
+    "@babel/compat-data": "workspace:^7.13.6"
     "@babel/core": "workspace:*"
+    "@babel/helper-compilation-targets": "workspace:^7.13.0"
     "@babel/helper-plugin-test-runner": "workspace:*"
     "@babel/helper-plugin-utils": "workspace:^7.13.0"
     "@babel/plugin-syntax-object-rest-spread": ^7.8.3